the study aims to assess the effectiveness of hydraulic pressure sinus lift via lateral wall approach, versus piezoelectric surgery in patients with deficient posterior maxilla.

This study involves a randomized clinical trial of 20 participants with less than 6 mm bone height in the posterior maxilla in need of Maxillary Sinus Floor Augmentation using the lateral window approach. Patients will be randomly assigned to two groups; the HPLT Group which include 10 patients who will undergo hydraulic pressure for osteotomy preparation for lateral sinus lifting technique, and the PSLT Group which include 10 patients managed using piezoelectric surgery. Clinical and radiographic assessment of bone augmentation, as well as intraoperative biological complications and postoperative complications were recorded.

Inclusion Criteria:

• The study included patient with deficient posterior maxilla with less than 6mm of bone height confirmed by a pre-operative tomographic scan. All healthy (ASA I, II) non- smoker patients were eligible for the study. The absence of uncontrolled diabetes, systemic illnesses, sinusitis, immune deficiency disorders, were also required for inclusion.

Exclusion Criteria:

• Patients with sinus infection, neoplasm or a large cyst of the sinus, or those who previously underwent a Caldwell-Luc surgery for the same surgical site were excluded

all data will be de-identified to protect the participant data. patients signed an informed consent for the use of their medical records and data for study

patients were allocated in a 1:1 ratio using an on-site computer software system with concealed allocation through sequentially numbered, opaque, sealed envelopes (SNOSE). This was a double-blind study, so neither the statistical analyst nor the patients were aware of the surgical procedure